Audience, Position and Process
UPDATE - This issue was inspired in a large part by conversations the GNOME community had leading up to the release of GNOME3.
Considering the work that RedHat has recently been put into GNOME Kiosk and the valuable work that has been done by Purism on making GNOME a viable option on handheld and tablet devices, is now the right time to think about introducing and designing core around the concept of flavours. Does it make sense to include GNOME-Shell for Kiosk, Phosh for Desktop etc.
#338 (closed) Seems to be a step in this flavour direction.
And as for collections, #150 (moved) #334 (closed) and #420 (closed) also seem to indicate a desire to pull as much out of core as possible and rely more on flatpak for installing, updating and removing non-essential applications.
I vaguely remember collections being a thing in the past, maybe with PackageKit or maybe I dreamt it up(UPDATE - on further research it seems there wasn't a way of selectively installing an application within a collection so maybe not). Would defining a set of collections for GNOME be desirable? A Development collection for Builder, Sysprof, D-Spy etc? A Multimedia Collection for Videos, Music and Photos. An Office collection for Abiword, Gnumetric, Dia etc